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Standard Operating Procedure (SOP) and Protocol for Calibration of Laboratory Glassware (Class A)  like- Volumetric flask, Pipette calibration, Burette calibration used in Quality Control Laboratory for analysis purpose.

Glassware Calibration Procedure

1.0   Purpose:

• • The purpose of this SOP is to describe the procedure for calibration of laboratory glassware.

2.0   Scope:

• • This SOP is applicable for calibration of laboratory glassware used in Quality Control Laboratory.

3.0   References:

• • IP-2020; 2.1.6. Volumetric Glassware

• • Manufacturer COA

4.0   Responsibilities:

• • Analyst:

• • To prepare the SOP.

• • To receive and calibrate the glassware as per procedure.

• • QC Head or designee:

• • To check the SOP.

• • Impart training to all concerned persons before implementations of SOP.

• • To ensure proper maintenance of respective documents.

• • Quality Assurance:

• • To check the SOP.

• • To ensure that implementation of system is as per SOP.

5.0   Procedure for Glassware Calibration:

• • General Procedure:

• • Review the manufactures certificates and put a review stamp on it.

• • To select the glassware (volumetric flask, pipette, burette) for calibration from fresh consignment or as and when required according to √ n+1 method.

• • If the calibration of the above is not within the limit, the consignments shall be returned to party.

• • Numbering of glassware shall be marked as follows :

QC/CAL/Z/YY/XXX

where,

QC   = Quality Control

CAL  = Calibration

Z  =  F (Volumetric Flask), P (Pipette), B (Burette)

YY   = Last two digit of year (eg;12, for year 2012)

XXX = serial number of glassware

• • Assign calibration ID No to each glassware which to be calibrated, accordingly.

• • Precautions during Glassware Calibration:

• • Handle glassware carefully.

• • Use clean and dry glassware for calibration.

• • Pipette/burette should be dried in vertical position and touched against wall of receiving vessel to drain the tips.

• • Use PPE’s such as nose mask, gloves etc. as per requirement during the handling of glassware.

• • Calculation:

%RSD    = 100/Xm x [Ʃ(Xi-Xm)²/n-1]½

Xm   = Mean value

Xi     = Individual value

n      = Number of analysis

• Calibration Protocol & Procedure for Volumetric Flask (Glassware):

Glassware Name		Template Issuance No.
Make		ID No.
Nominal Volume		Calibration date

Calibration Requirement:-

• • Balance                     Code No.______________    Valid upto _________

• • Digital Thermometer Code No.______________    Valid upto _________

• • Distilled water

Procedure for Volumetric Flask Calibration:-

• • Place the required amount of distilled water in beaker.

• • Allow the temperature of water to equilibrate to room temperature (25⁰C ± 2⁰C).

• • Weigh the dry empty flask on calibrated balance and note down the weight (W₁).

• • Record the observed temperature of water before pouring in volumetric flask (T₁).

• • Fill the flask to nominal volume with distilled water (25±2°C).

• • Weigh it again and note down the weight (W₂).

• • After weighing again record the temperature (T₂), the variation in temperature (ΔT) shall not be  more than ± 0.5⁰C  from the initial temperature of water.

• • Calculate the weight difference (ΔW) between empty flask (W₁) and flask with water (W₂)

• • Convert weight difference in terms of ml by calculating the wt/ml of water.

• • Calculate the error in ml and percentage.

• • Repeat the above step in triplicate.

• • Calculate the observed volume and relative standard deviation. RSD shall be with in 1.0%.

Calculations:-

           Weight difference(gm), ΔW =  W₂  –  W₁                   

           Observed Volume (ml), V_Observe =   ΔW/ D

Volume Difference(ml),ΔV  =  V_Nominal – V_Observe

ΔV                           

Relative Error (%)  =  —————— X 100                    

V_Nominal                                                  

where,

W₁ = Weight of empty flask                                  V_Nominal = Nominal Volume

W₂ = Weight of flask filled with water                 V_Observe = Observe Volume

D = Density of water at 25 ⁰C (0.997 g/ml)

Observations:-

Sr. No.	Water Temp. (OC)		Temp.Diff ΔT(OC)	Flask Weight (gm)		Weight Diff. ΔW (gm)	Observe Vol.(ml)	Vol. Diff. ΔV (ml)	Relative Error (%)
	Before Weight (T1)	After Weight (T2)	T2 – T1	Empty W1	Filled W2	W2 – W1	VObserve =  ΔW/D	VNominal – VObserve	ΔV/VNominal x 100
Mean
Limit: NMT 1%							%RSD

Acceptance Criteria:

Nominal Volume(ml)	5	10	20	25	50	100	200	250	500	1000
Class A Tolerance (± ml)	0.02	0.02	0.04	0.03	0.04	0.06	0.15	0.1	0.15	0.2
Relative Error (± %)	0.4	0.2	0.2	0.12	0.08	0.06	0.08	0.04	0.03	0.02

• Calibration Protocol & Procedure for Pipette (Glassware):

Glassware Name		Template Issuance No.
Make		ID No.
Nominal Volume		Calibration date

Calibration Requirements:-

• • Balance Code No.______________    Valid upto _________

• • Digital Thermometer Code No.______________    Valid upto _________

• • Distilled water

Procedures for Pipette Calibration:-

• • Place the require amount of distilled water in beaker.

• • Allow the temperature of water to equilibrate to room temperature (25⁰C ± 2⁰C)

• • Weigh the dry empty beaker on calibrated balance and note down the weight (W₁).

• • Record the observed temperature of water before pouring in pipette (T₁).

• • Fill the pipette to nominal volume with distilled water (25±2°C).

• • Transfer the filled volume to beaker, weigh it again and note down the weight (W₂).

• • After weighing, again record the temperature (T₂), the variation in temperature (ΔT) shall not be more than ± 0.5⁰C from the initial temperature of water.

• • Calculate the weight difference (ΔW).

• • Convert weight difference in terms of ml by calculating the wt/ml of water.

• • Calculate the error in ml and percentage.

• • Repeat the above step in triplicate.

• • Calculate the observed volume and RSD shall be within1.0%

Calculations :-

Weight difference(gm), ΔW =  W₂  –  W₁                      where,  

         Observed Volume (ml), V_Observe =   ΔW/ D                 V_Nominal  =  Nominal Volume

Volume Difference(ml),ΔV  =  V_Nominal – V_Observe         V_Observe = Observe Volume

ΔV                                            W₁  = Weight of empty beaker

Relative Error (%)  =  ——– X 100                      W₂  = Weight of beaker filled with water

V_Nominal                                                 D = Density of water at 25 ⁰C (0.997 g/ml)

Observations:-

Sr. No.	Water Temp. (OC)		Temp.Diff ΔT(OC)	Beaker Weight (gm)		Weight Diff. ΔW (gm)	Observe Vol.(ml)	Vol. Diff. ΔV (ml)	Relative Error (%)
	Before Weight (T1)	After Weight (T2)	T2 – T1	Empty W1	Filled W2	W2 – W1	VObserve =  ΔW/D	VNominal – VObserve	ΔV/VNominal x 100
Mean
Limit: NMT 1%							% RSD

 Acceptance Criteria:

Nominal Volume (ml)	1	2	5	10	20	25	50	100
Class A One Mark Pipettes
Tolerance (± ml)	0.01	0.01	0.02	0.02	0.03	0.03	0.04	0.06
Relative Error (± %)	1	0.5	0.4	0.2	0.15	0.12	0.08	0.06
Class A Graduated Pipettes
Subdivision (ml)	0.01	0.02	0.05	0.1	—	0.2	—	—
Tolerance (± ml)	0.006	0.01	0.03	0.05	—	0.1	—	—
Relative Error (± %)	0.6	0.5	0.6	0.5	—	0.4	—	—

 

Nominal Volume (ml)	3	4	6	9	15	—	—	—
Class A One Mark Pipettes
Tolerance (± ml)	0.01	±0.01	0.01	0.02	0.03	—	—	—
Relative Error (± %)	0.3	0.3	0.2	±0.2	0.2	—	—	—

• Calibration Protocol & Procedure for Burette (Glassware):

Glassware Name		Template Issuance No.
Make		ID No.
Nominal Volume		Calibration date

Calibration Requirements:-

• • Balance  Code No.______________    Valid upto _________

• • Digital Thermometer Code No.______________    Valid upto _________

• • Distilled water

Procedures for Burette Calibration :-

• • Place the require amount of distilled water in beaker. Allow the temperature of water to equilibrate to room temperature (25⁰C ± 2⁰C)

• • Take the weight of empty beaker (W₁).

• • Record the observed temperature of water before pouring in pipette (T₁).

• • Fill the burette to nominal volume with distilled water (25±2°C).

• • Transfer the volume to beaker, weigh it again and note down the weight (W₂).

• • After weighing, again record the temperature (T₂), the variation in temperature (ΔT) shall not be more than ± 0.5⁰C from the initial temperature of water.

• • Calculate the weight difference (ΔW).

• • Convert weight difference in terms of ml by calculating the wt/ml of water.

• • Calculate the error in ml and percentage.

• • Repeat the above step in triplicate.

• • Calculate the observed volume and relative standard deviation.

• • RSD shall be with in 1.0%.

Calculations:-

Weight difference(gm), ΔW =  W₂  –  W₁                      where,  

         Observed Volume (ml), V_Observe =   ΔW/ D                 V_Nominal  =  Nominal Volume

Volume Difference(ml),ΔV  =  V_Nominal – V_Observe         V_Observe = Observe Volume

ΔV                                            W₁  = Weight of empty beaker

Relative Error (%)  =  ——– X 100                      W₂  = Weight of beaker filled with water

V_Nominal                                                 D = Density of water at 25 0C (0.997 g/ml)

Observations :-

Sr. No.	Water Temp. (OC)		Temp.Diff ΔT(OC)	Beaker Weight (gm)		Weight Diff. ΔW (gm)	Observe Vol.(ml)	Vol. Diff. ΔV (ml)	Relative Error (%)
	Before Weight (T1)	After Weight (T2)	T2 – T1	Empty W1	Filled W2	W2 – W1	VObserve =  ΔW/D	VNominal – VObserve	ΔV/VNominal x 100
Mean
Limit: NMT 1%							%RSD

Acceptance Criteria:

Nominal Capacity (ml)	10 (micro)	25	50	100
Subdivision (ml)	0.05	0.05	0.1	0.1
Class A Tolerance (± ml)	0.01	0.03	0.05	0.1
Relative Error (± %)	0.1	0.12	0.1	0.1

Attachment : Volumetric flask calibration log book

Sr. No	Receiving date	Date of calibration	Nominal volume	Calibration ID	Calibrated By	Checked By

Attachment : Pipette calibration log book

Sr. No	Receiving date	Date of calibration	Nominal volume	Calibration ID	Calibrated By	Checked By

Attachment : Burette calibration log book

Sr. No	Receiving date	Date of calibration	Nominal volume	Calibration ID	Calibrated By	Checked By

Attachment : Template issuance log book

Sr. No	Date of issuance	Protocol issuance No	Glassware/ Volume	Glassware code No	Glassware calibration ID No	Issued By	Received By	Remark